grammar checker

• Correctness
• Grammar
• Lessons in Proofreading: Typos, Orpahs, and the Little Demon Titivillus
• Readability Formula
• Spellchecker
• Top Ten Proofreading Tips

Examples and Observations:

• "Your best friend may tell you that learning correct grammar in the third millennium is irrelevant because computer grammar checkers make human knowledge obsolete. Your friend is wrong.
  
  "It's comforting to think that a little green or red line will tell you when you've made an error and that a quick mouse click will show you the path to perfection. Comforting, but unreal. English has half a million words, and you can arrange those words a couple gazillion ways. No program can catch all your mistakes, and most programs identify errors that aren't actually wrong."
  (Geraldine Woods, Grammar Essentials For Dummies. Wiley, 2010)
• "Although the Spelling and Grammar Checker is a useful tool, there is no substitute for careful proofreading. Always take the time to read through your document to check for errors the Spelling and Grammar Checker might have missed. Keep in mind that the Spelling and Grammar Checker cannot pinpoint inaccurate phrases or poorly chosen words. You'll have to find those yourself. To produce a professional document, you must read it carefully several times. It's a good idea to ask one or two other people to read your documents as well; they might catch something you missed."
  (S. Scott Zimmerman et al., New Perspectives on Microsoft Word 2010. Cengage, 2011)

• Microsoft Word's Grammar Checker
  "Today, with the great majority of all PC users writing with Word, the consequence is a ubiquitous grammar-checking feature--a wavy green line that appears, seemingly at random in a PC user's word processing window, underscoring possibly errant phrases. Many users are baffled; others turn the feature off as an annoyance. . . .
  
  "Similarly, professional writers and editors tend to turn a jaundiced eye toward grammar checking. James Fallows, a writer at The Atlantic Monthly who once worked at Microsoft to try to improve the value of Word for writers and editors, said he could not recall a single instance in which he accepted the advice of Word's grammar checker.
  
  "He said that when he complained about Word's poor grammar-checking performance, Microsoft's developers defensively likened the grammar checker to an artificial leg--something useful for people who cannot walk otherwise."
  (John Markoff, "New Economy; A Computer Scientist's Lament: Grammar Has Lost Its Technological Edge." The New York Times, April 15, 2002)
• More Harm Than Good?
  "[H]ow much good does the grammar checker actually do? Precious little, according to Sandeep Krishnamurthy, an associate professor of marketing and e-commerce at the University of Washington. After experimenting with the tool, Mr. Krishnamurthy concluded that it cannot identify many basic grammatical faux pas--like errors in capitalization, punctuation, and verb tense. . . .
  
  "For above-average writers, the software might pick up a grammatical misstep or two, according to Mr. Krishnamurthy, but for subpar writers, the tool is useless.
  
  "Mr. Krishnamurthy says many of his students are not native English speakers and often struggle with the written word.
  
  "The grammar checker, he argues, impedes their efforts to improve their writing--by telling them that misconjugated verbs and poorly structured sentences are perfectly fine."
  (Brock Read, "Microsoft Word Grammar Checker Are No Good, Scholar Conclude." The Chronicle of Higher Education, April 15, 2005)
• Readability Statistics
  "Don't bother with the readability statistics. . . . The averages of sentences per paragraph, words per sentence, and characters per word have little relevance. The Passive Sentences, Flesch Reading Ease, and Flesch-Kincaid Grade Level are computed statistics that don't accurately assess how easy or hard the document is to read. If you want to know whether a document is hard to understand, ask a colleague to read it."
  (Ty Anderson and Guy Hart-Davis, Beginning Microsoft Word 2010. Springer, 2010)